The present invention relates to an image transfer type recording method for recording a color image on any type of medium such as plain paper, post card, clothes, plastic film, or the like.
A photosensitive and pressure-sensitive recording system which utilizes a photosensitive and pressure-sensitive recording medium comprising a substrate coated with pressure-rupturable microcapsules mainly encapsulating a chromogenic material or dye precursor, a photo-curing resin and a photopolymerization initiator and a developer medium comprising a substrate coated with developer material which is color-reactable with the chromogenic material or dye precursor has been conventionally used in an image forming apparatus. This recording system is disclosed in detail in Japanese Unexamined Published Patent Application No. 61-173981.
In this photosensitive and pressure-sensitive recording system, light is radiated onto the surface of the photosensitive pressure sensitive recording medium in accordance with an original image information to cure the photo-curing resin. Thereafter, the exposed photosensitive and pressure-sensitive recording medium is superposed over the developer medium under pressure to rupture the uncured microcapsules. As a result, the chromogenic material or dye precursor released from the ruptured microcapsules reacts with the developer material to form a visible image on the developer medium.
The photosensitive and pressure-sensitive recording system as described above can easily form an image on the developer medium which is specially manufactured, however, it can not form the image on any type of medium such as post cards, plain paper, plastic films (PET films), cloths and the like.
In order to resolve this disadvantage, the developer medium having the visible image thereon is superposed over a heat-fusible sheet comprising a base sheet coated with thermoplastic resin such that the developer material layer of the developer medium is contacted with the thermoplastic resin layer of the heat-fusible sheet, and then the superposed medium and sheet are applied with pressure and heat to thereby transfer only the developer material layer having the visible image from the developer medium to the heat-fusible sheet. Thereafter, the heat-fusible sheet to which the developer material layer is adhered, is adhered to any type of medium, and finally the base sheet is peeled from the heat-fusible sheet to attach the developer material layer having the visible image on any type of medium.
However, this adhesive sheet peeling process may often cause the following problems when the heat-fusible sheet is separated from the developer medium to peel the developer material layer having the visible image from the developer material layer, and/or from any type of medium to peel the base sheet from the heat-fusible sheet. In the former case, although the developer material layer should be separated from the substrate of the developer medium, the base sheet of the heat-fusible sheet is more easily separated from the thermoplastic resin layer thereof. Even when the developer material layer is completely separated from the substrate by the heat-fusible sheet and adhered to any type of medium, the base sheet of the heat-fusible sheet can not be easily and completely separated from the developer material layer. Therefore, the visible image formed on the developer material layer is often spoiled.
One of further improved image transfer type recording systems is provided to resolve the above problems, for example shown in Japanese Unexamined Published Patent Application No. 1-109760 and U.S. Ser. No. 497,360 filed on Mar. 22, 1990 (which corresponds to Japanese Unexamined Published Patent Application No. 1-109760). In this improved system, a developer material layer and a thermoplastic resin layer are coated on a single base sheet to form a developer medium. A visible image is developed on the developer medium by reacting the developer material and the chromogenic material or dye precursor deposited on a photosensitive and pressure sensitive recording medium. The developer medium is then superposed over any type of medium to be finally recorded, and the superposed mediums are supplied with pressure and heat. Finally, only the base sheet of the developer medium is peeled.
This image transfer recording system can easily, quickly and completely form the developer material image on any type of medium with a single transfer process. Further this system can also eliminate the difficulties with peeling work of the heat-fusible adhesive sheet. In this system, a heat roller or an ironing means is usually employed to heat and press the visible image on the developer medium and any type of medium. The temperature of the heat source such as the heat roller depends on the melting point of the developer material per se or a binder contained in the developer medium. If the temperature is low, the visible image can not be completely formed and transferred to any type of medium. In other words, this recording system is affected by ambient conditions. Even though the transferred image is formed on any type of medium by using the heat source at a low temperature, the transferred image would be easily separated from the surface of the medium.
Almost all conventional image transfer type recording systems can not completely and clearly form the transferred image on any type of medium, especially as a cloth surface. Even if the transferred image is clearly formed on the cloth surface, the transferred image has a poor adhesion thereto. As a result, such a transferred image is easily torn and broken by scratching and the like.